Non-patient related SARS-CoV-2 exposure to colleagues and household members impose the highest infection risk for hospital employees with and without patient contact in a German university hospital: follow-up of the prospective Co-HCW Seroprevalence study

BackgroundThe Co-HCW study is a prospective, longitudinal single center observational study on the SARS-CoV-2 seroprevalence and infection status in staff members of Jena University Hospital (JUH) in Jena, Germany. Material and MethodsThis follow-up study covers the observation period from 19th May 2020 to 22nd June 2021. At each out of three voluntary study visits, participants filled out a questionnaire on individual SARS-CoV-2 exposure. In addition, serum samples to assess specific SARS-CoV-2 antibodies were collected. Participants with antibodies against nucleocapsid and/or spike protein without previous vaccination and/or a reported positive SARS-CoV-2 PCR test were regarded as participants with detected SARS-CoV-2 infection. Multivariable logistic regression modeling was applied to identify potential risk factors for infected compared to non-infected participants. ResultsOut of 660 participants that were included during the first study visit, 406 participants (61.5%) were eligible for final analysis as they did not change the COVID-19 risk area (high-risk n=76; intermediate-risk n=198; low-risk n=132) during the study. Forty-four participants (10.8%, 95% confidence interval (95%CI) 8.0%-14.3%) had evidence of a current or past SARS-CoV-2 infection detected by serology (n=40) and/or PCR (n=28). No association of any SARS-CoV-2 infection with the COVID-19 risk group according to working place could be detected. But exposure to a SARS-CoV-2 positive household member (adjusted OR (AOR) 4.46, 95%CI 2.06-9.65) or colleague (AOR 2.30, 95%CI 1.10-4.79) significantly increased the risk of a SARS-CoV-2 infection. ConclusionOur results demonstrate that non-patient-related SARS-CoV-2 exposure imposed the highest infection risk in hospital staff members of JUH.